[ntp:questions] GPS/PPS and "enable calibrate"

Horvath Bob-BHORVAT1 Bob.Horvath at motorolasolutions.com
Fri Sep 6 13:20:06 UTC 2013

Sorry for top posting, but Outlook is quoting things correctly.

I did check out your site and based my original setup on it.  Lots of impressive stuff there!

The part I couldn't figure out the fudge time2 values.  Using the one that was pointed out to me by Wolfgang is working very nicely with the other image.  

I am curious how that value is determined.  I am assuming someone that understood it used the calibrate capability to come up with the 0.496 number that works for rpi-gpio cases. 

-----Original Message-----
From: questions-bounces+bob.horvath=motorolasolutions.com at lists.ntp.org [mailto:questions-bounces+bob.horvath=motorolasolutions.com at lists.ntp.org] On Behalf Of David Taylor
Sent: Friday, September 06, 2013 6:10 AM
To: questions at lists.ntp.org
Subject: Re: [ntp:questions] GPS/PPS and "enable calibrate"

On 05/09/2013 21:00, Horvath Bob-BHORVAT1 wrote:
> Hi,
> this runs perfectly for me:
> <http://open.konspyre.org/blog/2012/10/18/raspberry-pi-time-server/>.
> OK, maybe I'll have to try that image.
> In general though, when it comes to this line...
>    fudge flag1 1 time2 0.496
> ... how do you know what value to set for time2?
> Did you got through the instructions here?
> http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver20.html
> ... or are you using 0.496 - what is shown on the http://open.konspyre.org/blog/2012/10/18/raspberry-pi-time-server/ ?
> Bob

No need to change the Kernel,Bob.  There's a program which does /not/ require you to change the OS - it runs the PPS collection in user-mode rather than kernel-mode, and the performance is only a shade worse than the kernel-mode version:




All my Raspberry Pi experiments with different NTP versions and different GPS receivers are here:


so I hope you find something of interest there.

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